He was the charismatic pop star of East Berlin’s oppositional literary scene in Prenzlauer Berg in the eighties, a close acquaintance of Christa Wolf, Franz Fühmann and Heiner Müller. He was also a zealous informer working for the GDR’s secret police: Sascha Anderson, born 1953. Twenty years on, the pain he inflicted on friends and colleagues is as deep-seated as ever and the f...